Spacewalking astronauts install power tower to international space station; spot rip on panel

AP Photo/NASA TVIn this image taken from NASA television, a rip is seen in a second solar panel as it was unfurled after it was installed Tuesday by spacewalking astronauts Scott Parazynski and Douglas Wheelock. The astronauts abruptly stopped the unfurling of the second panel, however, as soon as they spotted the rip.

HOUSTON -- Spacewalking astronauts bolted a solar power tower to the international space station on Tuesday, completing an ambitious three-day moving process that ended with elation when the beam's giant solar panels began to unfurl.

Their joy turned to concern, however, when a rip was spotted in the second solar panel.

NASA needs to get the tower up and running to prevent malfunctioning station equipment from delaying the addition of a much-anticipated European research lab.

A massive rotary joint is supposed to make sure the solar panel wings on the right side of the space station are facing the sun. But the gear, which was installed in June, has been experiencing electrical current spikes for nearly two months.

The solar panels on the 17 1/2-ton girder that was installed at its new location Tuesday were folded up like an accordion for the move, and the first one slowly was unfurled as the seven-hour spacewalk wrapped up, gleaming like gold in the sun.